For particular types of finishing and forming operations, diamond grinding wheels are used. For example, resin bonded, diamond grinding wheels are required where close tolerances and extremely smooth finishes are necessary, as in the forming of carbide and tungsten carbide tools. Bonded grinding wheels incorporating boron nitride as an abrasive have also proven to be satisfactory for many of these same applications, with the exception of carbide grinding. Boron nitride is a manufactured abrasive having qualities of hardness similar to diamond. Such grinding wheels, like abrasive wheels of any kind, must be trued or dressed from time to time as they wear in order that they may accurately form fine finishes or precise contour on work pieces, such as tools. Precision grinding utilizing diamond and boron oxide wheels is becoming less and less popular because it is so difficult to establish and maintain the proper dress on such grinding wheels. The silicon carbide and aluminum oxide tools used in the past to dress grinding wheels of this type wear away so rapidly when held in frictional contact with a rotating diamond or boron oxide wheel during a dressing operation that it is extremely difficult to accurately dress such wheels with these tools. Even if sufficient material can eventually be removed from wheels having such hard abrasives as diamond and boron oxide using such tools in a dressing operation, the tremendous wear rate of such tools against wheels of this type requires the use of excessive quantities of silicon carbide or aluminum oxide tools. Also, the heat and dust generated in using silicon carbide or aluminum oxide tools to dress diamond or boron nitride grinding wheels is highly undesirable.
I have discovered that the aforesaid difficulties can be overcome, and that the highly effective, accurate and economical truing and dressing of a bonded, diamond or boron nitride grinding wheel can be accomplished using a molybdenum tool or a tool made of the closely related metals tantalum and columbium.